I gotta be one of the most pro-vape people on the planet, because I firmly believe that vaping has dramatically improved my life, and very likely extended it. With that said:
I'm still not sure how some can't seem to understand, that when most people walk into a room and see someone a.) blowing what initially LOOKS like smoke out of their mouths; OR b.) putting some unfamiliar 'instrument' to their mouth and inhaling on it, that it sure LOOKS like smoking, or, maybe like imbibing something that could be illegal to the uninitiated.
Can we not all agree, that there is just no getting past the fact that until vaping becomes far more accepted than it already is, that there will certainly be resistance from certain types. This will ALWAYS be the case.
This is really a simple, small problem that is easy to overcome to most everyone's satisfaction, in my opinion. I have vaped in places that some would probably not believe (and that I will not go into here) that I could never get away with smoking a cigarette. All I did was exercise a little bit of discretion, courtesy, and stealth. (So I consider myself way ahead of the game!)
I really believe that if you vape in people's faces or generally just in their presence, you should expect that some will complain, if not get in your face as well. This is really not likely to EVER change, no matter how much vaping is accepted.